POS0988 ANKYLOSING SPONDYLITIS (AS) ACTIVITY DURING THE YEAR AFTER CHILDBIRTH.
Authors: O. Krichevskaya, E. Ilinykh, T. Dubinina, S. Glukhova, A. Demina, I. Andrianova
Journal: Annals of the Rheumatic Diseases (2022)

Background Currently, data on the course of AS during pregnancy are being accumulated. However, information about the activity of AS in the postpartum period including against the background of lactation, remains scanty and contradictory. Objectives To assess the dynamics of activity of AS during the year after childbirth, to identify predictors of high activity. Methods 44 women with confirmed AS (modified New York criteria, 1984) were followed within 1 year after childbirth. The visits were carried out in 1, 6 and 12 months after delivery. The average age of the patients was 32,5 ± 5,8 years, the duration of the disease was 149,0 ± 96,3 months. The activity according to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in the 1st, 2nd and 3rd trimesters of pregnancy was 2,8 ± 1,9; 2,9 ± 1,9 and 2,7 ± 1,8, respectively. The Ankylosing Spondylitis Disease Activity Score CRP (ASDAS-CRP) was 1,8 [1,6; 2,5]; 2,1 [1,5; 2,9] and 2 [1; 3,5], respectively. Delivery period was 39,0 ± 1,2 weeks. Lactation was established in 40 women and the duration was 10 [4; 12] months. Results Subjective deterioration of well-being was noted by 36 (81,8%) women after 8 [4; 17] weeks after delivery, while 29 (65,9%) patients associated deterioration of well-being with increased activity of AS, including recurrence of uveitis and arthritis, and 7 cases of increased severity of back pain of mechanical rhythm was revealed. 1 month after delivery, 39 patients (88,6%) reported back pain with NRS intensity of 3,0 [2,0; 6,0]; night pain – 29 women with intensity of 3,0 [2,0; 6,0]. 6 months after delivery, back pain was observed in 38 (86,4%) patients, its intensity was 4,0 [3,0; 5,0]; nocturnal pain – in 32 women with intensity of 3,0 [2,0; 5,0]. 12 months after delivery, 33 (75%) women experienced back pain with NRS intensity of 4,0 [3,0; 6,0]; Night pain – 27 women with intensity of 2,0 [1,0; 4,0]. The BASDAI at 1, 6 and 12 months after giving birth was: 2,4 [1,4; 4,2]; 2,6 [1,4; 4,4]; 2,7 [1,5; 4,1], respectively (p &gt; 0,05). ASDAS-CRP was 2,0 [1,2; 2,7]; 1,9 [1,4; 2,5]; 1,7 [1,3; 2,3], respectively (p &gt; 0,05). CRP level – 3,4 [2,0; 8,6], 3,5 [1,0; 7,8] and 2,6 [0,8; 8,2] mg/l, respectively (p &gt;0,05). There were no differences between activity during 1 year after childbirth and during pregnancy. There were no differences between the values of BASDAI, ASDAS-CRP, CRP, and the severity of night pain between women with and without lactation. Predictors of high AS activity (BASDAI ≥ 4) 1 month after delivery were: BASDAI ≥ 4 in the 1st trimester (OR 8,1; 95% CI 1,8 – 37,0; p = 0,006) and 2nd trimesters of pregnancy (OR 5,1; 95% CI 1,2 – 20,6; p = 0,02); NRS back pain &gt; 4 in the 2nd trimester (OR 4,3; 95% CI 1,1 – 17,2; p = 0,04); cancellation of bDMARD therapy in the 1st trimester of pregnancy (OR 21,0; 95% CI 1,0 – 440,9; p = 0,05). Predictors of high AS activity in 6 months after delivery were: BASDAI ≥ 4 in the 1st trimester (OR 6,5; 95% CI 1,5 – 28,7; p = 0,01), in the 2nd (OR 6,7; 95% CI 1,6 – 27,8; p = 0,009) and in the 3rd trimesters of pregnancy (OR 8,7; 95% CI 1,9 – 38,6; p = 0,005); high activity in 1 month after delivery (OR 4,0; 95% CI 1,0 – 15,9; p &lt; 0,05). The predictor of high activity in 12 months after delivery was high activity 6 months after delivery (OR 8,3; 95% CI 1,9 – 37,2; p = 0,005). Conclusion There was no increase in AS activity according to BASDAI and ASDASCRP within 1 year after childbirth, while 66% of women noted a subjective deterioration of well-being associated with AS symptoms intensification. High AS activity during pregnancy was a risk factor for high activity within 6 months after delivery. Given the generally accepted opinion that AS activity at the time of conception is a predictor of activity during gestation, we can talk about the importance of pregnancy planning from the point of view of the postpartum period. Further studies on large groups of patients are required to clarify the dynamics of AS activity after childbirth. Disclosure of Interests None declared